Physics of Atomic Energy Levels and Emission Spectra, Exams of Physics

Download Physics of Atomic Energy Levels and Emission Spectra and more Exams Physics in PDF only on Docsity! Modern Physics CTs CTMP-1 A Neon lamp emit a strong red line. Sodium emits a strong yellow line. What accounts for this difference? A) The electrons in the discharge tube hit the neon atoms with more speed than the electrons hit the sodium atoms B) The electrons in the discharge hit the neon atoms with less speed than the electrons hit the sodium atoms C) The energy spacing between the electronic energy levels in the neon atom are smaller than in the sodium atom. D) The energy spacing between the electronic energy levels in the neon atom is larger than in the sodium atom. Answer: Yellow light is shorter wavelength than red light. So yellow photons are higher energy (E = hc/ and higher energy photons correspond to larger energy spacing between allowed energy levels. The energy spacing between the electronic energy levels in the neon atom are smaller than in the sodium atom. CTMP-2 When an emission line (color) appears brighter, that means: A) Multiple photons are emitted for each electron transition B) More electron transitions are occurring each second C) The electronic energy levels are farther apart and thus the line appears brighter D) A and B E) B and C Answer: More electron transitions are occurring each second. Each transition causes only 1 photon, so brighter lines means more photons, more transitions. CTMP-3 The spectrum of "Perkonium" has 3 emission lines Which energy level structure is consistent with the spectrum? Answer: Only (C) fits the spectrum wavelength(nm)200 300 400 500 600 5 eV 3 eV 2 eV E(eV) –2 –3 –5 –2 –4 –5 –7 –7 –5 –10 –5 –7 –8 (A) (B) (C) (D) –7 –5 –10 E(eV) 2 eV 3 eV 5 eV